Runaway World

The Sentry Weapon

     "The slope's too steep to the west," Cheval replied. "I've made accidental contact with the ice with my knees several times already. I don't want to get frostbite."

     "You don't want to get your head vaporised by a fifty kilowatt laser beam either. Keep to the west."

     "We'll try." Cheval looked around, assessing the irregular terrain as best he could. The sun had dropped below the western mountains some time ago leaving them in almost total darkness and he was relying on his helmet light to see by. "I think there's a way up over beside that rock," he said to Andrew.

     Andrew looked. As he raised his head, though, his helmet light spilled across the bare rocks further up, rocks that had to have been in sight of the sentry weapon. He quickly ducked back down again. "How does it spot targets?" he asked. "Will it target a moving spot of light?"

     "Target?" Cheval replied. "No, but it will attract its attention to the area. It has low resolution microwave motion sensors and visible light cameras looking in all directions all the time, but if something attracts its attention it'll direct its high resolution camera towards it. The thing is supposed to be quite smart. At least corvid level intelligence."

     Andrew nodded anxiously. "And how long will its attention stay in that area, assuming it doesn't spot anything?"

     "Depends on what it learned when it was last active. If nobody came this way during The Freeze it'll only have the knowledge and experience that was programmed into it in the factory, but if it saw any action, if people tried to get past it during The Freeze, it will have gained new experiences."

     "You think any of them will have tried what we're trying?"

     "There were six sentry weapons stationed here back then, along with a whole battery of cannons and machine guns. The gap in its defences didn't exist back then."

     "You said it's smart. Is it smart enough to know that it's vulnerable from above and adapt its behaviour accordingly?"

     "Your guess is as good as mine."

     Well, that's reassuring, thought Andrew as he edged his way along to the rock Cheval had spotted. Reaching it, though, he was relieved to see that the way was easier from there on. The slope was less steep and there were knobs of bare rock protruding through the ice that his boots could get a good grip on. The cleats would be getting blunted, though. He would have some maintenance work to do when he got back to the rover.

     An hour went by as they continued to climb, and then another hour in which they made their way eastwards along a more or less level ledge that might once have been a footpath. There was a mummified body lying on the path, dressed in thick furs, the flesh so perfectly preserved and so perfectly white that it looked like a marble sculpture except for the burns around the eyes. Andrew looked around for the weapon that had killed him and saw it about a hundred metres away to the west, barely visible in the starlight. It was dark and dead. A piece of modern art left behind by a lost and forgotten civilisation. He watched it just in case, remembering Cheval's warnings that some of the ancient weapons might still be operational even in the absence of Fox's attention, but the stubby barrel of the laser was pointing the other way and didn't move. Breathing a sigh of relief he continued on his way.

     "This is taking too long," he said as they reached the highest point and began to descend the other side. "We won't get back to the rover in time. We'll run out of power."

     "The weapon may have an external power point," Cheval replied. "We'll be able to recharge our suits."

     "May?" said Andrew in alarm. "It may have?"